[Dragncar]

I am making my own pickup for my Steffs oil pan.

There is a issue others have talked about with say a Canton pickup. The dia is small, turns are tight and the pickup itself is a rectangle with hole to one far side.
Not good. people have reported oil pressure dipping on acceleration.
I talked to Mark Luhn about this and he told me things they did. I am doing something they used to do with my own twist to it. He said a lot of engines blow up because of this issue. And I can not have that !
I bought a slightly larger pickup (Ford I think) with a proper cone shaped pickup itself.
Tube is .814 vs .750 stock. Its no much larger but if you understand flow in a pipe you would know that a small increase in the size of the circle gives a much larger increase in flow.
So I bored the pump out for a slight press fit. Chopped the long pickup into sections I could put to use. And to solve my issue of two 90* corners needed I used a 1 3/4" long section of 1" pipe.
Thinking sort of like a 'fuel log" for a carb. You can make 90* turns if one pipe is much larger than the other so the liquid can make the turn without restriction.
I had to drill 2 13/16 holes in the 1" pipe. One for a short section of pickup tube to go the the pump. And the other for the cone shaped pickup itself.
I cut a slices out of a piece of 1 1/4" shaft to cap the 1" pipe for the last step of the process.

[Dragncar]

Its a lot of messing around. Fitting, checking, mocking up.

My pan is 8 3/8 " deep on the inside. So I set the pickup level 8 1/4" off the pan rail. So once gasket is in there I have right at 3/8" clearance pan to pickup, perfect.
Will clean and get the caps welded on tonight. Then have to fabricate a strap from bolt hole in pump to pickup to make sure it can not fall off.

[steve25]

That looks great, but the main great thing about the stock pick up location is that since near the whole body of the pump is in the oil it does not have to make much suction at all to do the job of getting oil into itself.

It self primes on start up!

You look at some of the long pickup tubes on some Ford motors and it’s know wonder they knock as they do on cold starts!

In short I hope the level / amount of oil in your sump will height wise at least cover the top of the oil intake hole in the pump body?
This is also the reason why a small amount of positive pressure in the crankcase is not a bad thing in terms of forcing oil into the pump,

[Tom Vaught]

Originally Posted by steve25

This is also the reason why a small amount of positive pressure in the crankcase is not a bad thing in terms of forcing oil into the pump,

You already have 14.7 psi of atmospheric pressure (at sea level) pushing on the oil in the crankcase to enter the oil pump.

Positive pressure in the oil pan above that 14.7 psi suggests that you have a lousy sealing ring package installed on your pistons.

Tom V.

[Dragncar]

Originally Posted by Tom Vaught

You already have 14.7 psi of atmospheric pressure (at sea level) pushing on the oil in the crankcase to enter the oil pump.

Positive pressure in the oil pan above that 14.7 psi suggests that you have a lousy sealing ring package installed on your pistons.

Tom V.

Tom, am I right about the 2 tubes and the 90* turn. One being much larger so there is no restriction ? The whole pickup should be in oil. I will post up some pics with the pump and pickup all together when I am done.
Thanks.

[Tom Vaught]

Originally Posted by Dragncar

Tom, am I right about the 2 tubes and the 90* turn. One being much larger so there is no restriction ? The whole pickup should be in oil. I will post up some pics with the pump and pickup all together when I am done.
Thanks.

The restriction is now the short "stub" you have going into the oil pump.
The restriction, size of the pipe there is not as important as what you did with the inlet into that short "stub". If that short "stub" has a sharp edge on it anywhere vs the smooth stock oil pick-up tube, then the flow drops a bunch.
Sometimes in some flow applications (with air for example) as much as 40% less flow. I would have made that specific piece a very smooth radiused inlet BEFORE I stuck it into the larger common pipe you are using to make the "Turn" into the pump. Radius BEFORE WELD.

Tom V.

[Scott Stoneburg]

For reference, this is how i did mine, using the same pick up tube to start with, thank you Dragncar for the part number on the tube. I brazed the pick up screen back to the tubing instead of trying to weld it because of my skill set..lol...

[steve25]

This is the best possible form/ area change for getting fluid or air around a bend in the least possible run length!

It can provide nearly twice the flow area even around a 180 degree bend, no less 90 degree!

I have a patient pending on this form so think twice!

[Dragncar]

Originally Posted by steve25

This is the best possible form/ area change for getting fluid or air around a bend in the least possible run length!

It can provide nearly twice the flow area even around a 180 degree bend, no less 90 degree!

I have a patient pending on this form so think twice!

That looks like some of the joints I have seen on some industrial fire sprinkler systems. They are cast and bolt onto the pipes with rubber rings and receiver groves in the pipe.
its been engineered right !

[ErikW]

This is what you need. They can sell you one with the pickup not welded and you set pickup height then weld.
http://www.luhnperformance.com/pontiac.html

[slowbird]

By increasing the feed size have you really increased much on the output side? The gear size in the pump dictates the volume moved per revolution does it not?
What exactly is being accomplished by increasing the feed size? Is the normal/stock size restrictive to the pump?

[johnta1]

A too small pickup tube would cavitate (adding air instead of oil).
Probably happen at a higher RPM.

[slowbird]

Originally Posted by johnta1

A too small pickup tube would cavitate (adding air instead of oil).
Probably happen at a higher RPM.

I can see that but do we think that's currently an issue? I spun my Mellings with stock sized pickup to 8200rpm without oiling issues. That was with 13-14" of vacuum in crank case so no 14.7psi of atmosphere helping to push oil into pump.

[Scott Stoneburg]

Originally Posted by slowbird

I can see that but do we think that's currently an issue? I spun my Mellings with stock sized pickup to 8200rpm without oiling issues. That was with 13-14" of vacuum in crank case so no 14.7psi of atmosphere helping to push oil into pump.

It may not be an issue, but a larger dia inlet cant hurt anything either.

[slowbird]

Originally Posted by Scott Stoneburg

It may not be an issue, but a larger dia inlet cant hurt anything either.

I totally agree if you're able to do the mods youself. Otherwise one needs to weigh the benefits vs the added cost of buy a pump with the in large inlet.
Alot of stuff has no downside to doing it but it does add cost to the build while providing very little upside. It's very easy to go way beyond the budget when building engines. And since this is the street section, im assuming most of the builds here are budget minded lower hp lower rpm builds.

[Dragncar]

Originally Posted by slowbird

By increasing the feed size have you really increased much on the output side? The gear size in the pump dictates the volume moved per revolution does it not?
What exactly is being accomplished by increasing the feed size? Is the normal/stock size restrictive to the pump?

All the indications show the stock size tube is a little small under some conditions. Luhn's oil pump dyno setup have proved it. Its one the stab of the throttle from say 2000 RPM to redline it takes a split second for the pressure to catch up.
Thats what I am trying to avoid.

[Tom Vaught]

Originally Posted by slowbird

By increasing the feed size have you really increased much on the output side? The gear size in the pump dictates the volume moved per revolution does it not?
What exactly is being accomplished by increasing the feed size? Is the normal/stock size restrictive to the pump?

Like another member suggested call Luhn for the reason why it works.

If at 8000 rpm you do not have time to FULLY fill the spaces between the gear teeth then you are not pumping the highest volume of oil thru the engine for that given pump rpm. Having a proper inlet size allows the oil to fill those spaces between the gear teeth more efficiently.

If you are not filling the spaces properly with a stock height gear tooth set-up as produced by Melling for the Pontiac engine, then how can you expect to fill an even larger tooth volume (when using a BB Chevy "TALLER" gear set installed in the pump, for example. If you read the one post mentioning flow volumes the Pontiac gear set flows 13 gallons a minute and the BB Chevy parts flow 19 gallons a minute. This is Melling oil pump data.

By that same logic you are saying that you do not need a Titan Gerotor oil pump that many have installed in
their race engines.

Tom V.

I was always taught that one fact was worth one Thousand Opinions.

[slowbird]

Originally Posted by Tom Vaught

Like another member suggested call Luhn for the reason why it works.

If at 8000 rpm you do not have time to FULLY fill the spaces between the gear teeth then you are not pumping the highest volume of oil thru the engine for that given pump rpm. Having a proper inlet size allows the oil to fill those spaces between the gear teeth more efficiently.

If you are not filling the spaces properly with a stock height gear tooth set-up as produced by Melling for the Pontiac engine, then how can you expect to fill an even larger tooth volume (when using a BB Chevy "TALLER" gear set installed in the pump, for example. If you read the one post mentioning flow volumes the Pontiac gear set flows 13 gallons a minute and the BB Chevy parts flow 19 gallons a minute. This is Melling oil pump data.

By that same logic you are saying that you do not need a Titan Gerotor oil pump that many have installed in
their race engines.

Tom V.

I was always taught that one fact was worth one Thousand Opinions.

Not saying im right or wrong just that 8000rpm with melling pump showed zero signs of oiling issues in my engine.
Like i stated if someone can do these mods themselves or has the extra cash flow to pay for it great. But people need to weigh the cost vs benefit if they're on a budget. And again this is the street section not the race section.

[Tom Vaught]

Originally Posted by slowbird

Not saying im right or wrong just that 8000rpm with melling pump showed zero signs of oiling issues in my engine.

I am not saying you are wrong or right either, I am just saying you do your thing with your engine and let other people do their thing with their engine.

So how often does your dad or you buzz your engine up to 8000 rpm on the street? If you don't do that then what does a Drag Strip Mode of operation by you have to do with street operation?

Just wondering This thread is about engine oil pump mods that worked for some. Same deal with aftermarket cylinder heads, why install them if it is a "STREET" car?

Tom V.

[ErikW]

Call Luhn and they'll explain it to you